C++ Program To Implement Matrix Operations

#include<iostream.h>
#include<conio.h>
#include<stdlib.h>
int m,n,p,q;
class mat
{
int mt[10][10];
public: void add(mat m1,mat m2);
void sub(mat m1,mat m2);
void mul(mat m1,mat m2);
void transpose();
void read_matrix();
void display_matrix();
};

void mat::add(mat m1,mat m2)
  {
    for(int i=0;i<m;i++)
      for(int j=0;j<n;j++)
mt[i][j]=m1.mt[i][j]+m2.mt[i][j];
  }
void mat::sub(mat m1,mat m2)
  {
  for(int i=0;i<m;i++)
    for(int j=0;j<n;j++)
      mt[i][j]=m1.mt[i][j]-m2.mt[i][j];
  }
void mat::mul(mat m1,mat m2)
  {
  for(int i=0;i<m;i++)
    {
      for(int j=0;j<q;j++)
{
 mt[i][j]=0;
   for(int k=0;k<p;k++)
     mt[i][j]=mt[i][j]+m1.mt[i][k]*m2.mt[k][j];
}
    }
}
void mat::transpose()
{
  for(int i=0;i<n;i++)
    {
      for(int j=0;j<m;j++)
{
 cout<<"\t\t"<<mt[j][i];
}
cout<<"\n";
    }
}

void mat::read_matrix()
  {
    for(int i=0;i<m;i++)
      for(int j=0;j<n;j++)
cin>>mt[i][j];
  }

void mat::display_matrix()
  {
    for(int i=0;i<m;i++)
      {
for(int j=0;j<n;j++)
 {
   cout<<"\t\t"<<mt[i][j];
 }
      cout<<"\n\n";
     }
}

void main()
{
  mat m1,m2,msum,msub,mmul,mtrans;
  int ch;
  clrscr();
  cout<<"\nmatrix operations\n";
  cout<<"\nenter your choice\n";
  cout<<"\n1.addition\n2.subtraction\n3.multiplication\n4.transpose\n5.exit\n";
  cin>>ch;
  switch(ch)
  {
  case 1: cout<<"\nmatrix addition\n";
  cout<<"\nenter the row & column values for 1st matrix:";
  cin>>m>>n;
  cout<<"\nenter the row &column values for 2nd matrix:";
  cin>>p>>q;
       if((m!=p)||(n!=q))
       {
cout<<"\nmatric addition is not possible\n";
       getch();
     exit(0);
  }
  cout<<"\nenter the elements for 1st matrix\n";
  m1.read_matrix();
  cout<<"enter the elementes for 2nd matrix\n";
  m2.read_matrix();
  cout<<"the 1st matrix is\n";
  m1.display_matrix();
  cout<<"the 2nd matrix is \n";
  m2.display_matrix();
  cout<<"\naddition of two matrices\n";
  msum.add(m1,m2);
  msum.display_matrix();
  break;
 case 2: cout<<"\nmatrix subtraction \n:";
 cout<<"\nenter the row & column values for 1st matrix:";
  cin>>m>>n;
  cout<<"\nenter the row &column values for 2nd matrix:";
  cin>>p>>q;
  if((m!=p)||(n!=q))
   {
   cout<<"\nmatrix subtractioin not possible\n";
   getch();
   exit(0);
   }
 cout<<"\nenter the elements for 1st matrix\n";
 m1.read_matrix();
 cout<<"\nenter the elements for 2nd matrix\n";
 m2.read_matrix();
 cout<<"the 1st matrix is\n";
  m1.display_matrix();
  cout<<"the 2nd matrix is \n";
  m2.display_matrix();
 cout<<"\nsubtraction of two matrices is \n";
 msub.sub(m1,m2);
 msub.display_matrix();
 break;
 case 3: cout<<"\nmatrix multiplication\n";
 cout<<"\nenter the row & column values for 1st matrix:";
  cin>>m>>n;
  cout<<"\nenter the row &column values for 2nd matrix:";
  cin>>p>>q;
 if(n!=p)
   {
   cout<<"\nmatrix multiplication not possible\n";
   getch();
   exit(0);
   }
 cout<<"\nenter the elements for 1st matrix\n";
 m1.read_matrix();
 cout<<"\nenter the elements for 2nd matrix\n";
 int tm=m;
 m=p;
 n=q;
 m2.read_matrix();
 m=tm;
 cout<<"the 1st matrix is\n";
  m1.display_matrix();
  cout<<"the 2nd matrix is \n";
  m2.display_matrix();
 cout<<"\nmultiplication of two matrices is \n";
 mmul.mul(m1,m2);
 n=q;
 mmul.display_matrix();
 break;
 case 4: cout<<"\nmatrix transpose\n";
 cout<<"\nenter the row & column values for 1st matrix:";
  cin>>m>>n;
  cout<<"\nenter the row &column values for 2nd matrix:";
  cin>>p>>q;
  cout<<"\nenter the elements for matrix\n";
 mtrans.read_matrix();
 cout<<"\nthe entered matrix is\n";
 mtrans.display_matrix();
 cout<<"\nafter transposing matrix is \n";
 mtrans.transpose();
 break;
 default:exit(0);
 }
 getch();
}